Sodium alkyl ether sulfate c{hd 12{b -c{hd 14 {b soap blends for optimum sudsing in hard surface cleaners

ABSTRACT

Detergent compositions containing water-soluble alkyl ether sulfate/soap blends which provide optimum sudsing during cleaning operations are disclosed.

Unlted States Patent 11 1 1111 3,862,050 Aubert 1 1 Jan. 21, 1975 [5 1SODIUM ALKYL ETHER 3,211,661 10/1965 Smith 1. 252/153 SULW?TIEC12- C14 PL DS O 3,281,367 10/1966 Jones et a1 OPTIMUM SUDSING IN HARD SURFACEE233 252/117 CLEANERS [75] Inventor: Harry J. Aubert, Center Twsp.,FOREIGN PATENTS OR APPLICATIONS Dearbom County Ind 1,180,114 4 1970Great Britain 252/321 855,893 12/1960 Great Britain 1 252/551 [73]Assignee: The Procter & Gamble Company, 797,119 6/1958 Great Britain252/551 OTHER PUBLICATIONS [22] Flled: June 1971 Phosphate Replacements:Problems with the Wash- [21] Appl. No.: 158,596 day Miracle, by Allen L.Hammond, Science, Vol.

172, pages 361-363, Apr. 23, 1971.

[52] US. Cl 252/117, 252/110, 252/121, Primary Examiner Mayer Weinblatt252/532, 252/551, 252/DIG. 14 A E D 1 L Alb h 51 Int. Cl. Clld 9/12, c11d 9/32,C11d 9/46 f zs g s JG Richard [58] Fleld of Search 252/110, 121,117 0 wine; Julius P. Filcik [56] References Cited UNITED STATES PATENTS1571 ABSTRACT 2,560,839 7/1951 Ayo et al. 252/109 Detergent CompositionsContaining Water-Soluble dlkyl 2,954,347 9/1960 St. John et a1. 252/109ether sulfate/soap blends which provide optimum 3,052,635 9/1962 Wixon252/528 sudsing during cleaning operations are disclosed. 3,086,9444/1963 Wedell 252/321 X 3,179,599 4/1965 Eaton et al. 252/153 7 ClalmS,N0 Drawmgs SODIUM ALKYL HE S LEATE c,,-c SOAP BLENDS FOR OPTIMUM SUDSINGIN HARD SURFACE CLEANERS FIELD OF THE INVENTION This invention relatesto detergent compositions suitable for hard surface cleaning; moreparticularly it relates to liquid detergent compositions comprisingalkyl ether sulfate and fatty acid soap blends. These alkyl ethersulfate/soap blends are characterized by desirable sudsing profiles,i.e., those which are not too high initially and fairly stablethereafter.

The cleaning power of a liquid detergent is frequently judged by thehousewife as directly related to the sudsing profile of the detergent.Consequently, a detergent which does not exhibit desirable sudsingcharacteristics during the cleaning operation is considered by thehousewife, in some cases, to be an inferior cleaning product. Similarly,a composition having excess suds tends to be considered undesirableinsofar as rinsing operations, particularly on hard surfaces, arehampered. Ideally, a suitable cleaning composition should initially havea desirable level of sudsing and a fairly constant suds level duringcleaning operations so as to connote desirable cleaning effects andshould not suds excessively.

A detergent composition suited for hard surface cleaning operationsshould also be capable of providing cleansing action without harmfuleffect on the cleansed surfaces or on the skin of the user.

It is therefore an object of this invention to provide detergentcompositions having improved sudsing characteristics in hard surfacecleaning operations (i.e., not too high initially and fairly stablethereafter).

It is a further object of this invention to provide detergentcompositions capable of washing tile floor, appliances, painted wallsand the like without damage to the surface.

It is yet another object of this invention to provide a detergentcomposition which does not adversely effect the hands of the individualduring cleaning operations.

SUMMARY OF THE INVENTION These and other objects which will becomeapparent from the following detailed description'are attained inaccordance with the present invention by the provision of liquid hardsurface cleaning compositions which comprise: an alkyl ether sulfate (AES) of the formula wherein R is alkyl of from to 16 carbon atoms, x hasan average value of from 1 to 10, especially from 2 to 4 and M is alkalimetal, ammonium, or substitutedammonium; an alkali metal fatty acid soaphaving from 12 to 14 carbon atoms; and the balance water; said alkylether sulfate and alkali metal soap being in a weight ratio of from 1:1to 30:1.

These hard surface cleaning compositions are characterized by optimumsudsing profiles for cleaning operations. They provide sufficientsudsing levels as to connote desirable cleaning operations. They aresuited to the cleaning of waxed floors and other surfaces withoutwax-removal thereby leaving a rebuffable surface and are not harsh onthe skin.

The detergent compositions of the invention can obtain a water-solubleinorganic or organic alkaline builder salt. Suitable weight ratios ofdetergent (AE S and soap) to builder are from about 4:1 to 1:20. Thepreferred ratio of the detergent to builder is 1:1 to about 1:10.

DETAILED DESCRIPTION OF THE INVENTION An essential detergent componentof the hard surface cleaning compositions of the invention comprises asulfated and neutralized ethoxylate detergent. The sulfated andneutralized ethoxylate detergents of the invention are well known. Theirpreparation and properties are described, for example, in British Pat.No. 791,704 (Mar. 12, 1958); British Pat. No. 797,119 (June 25, 1958);US. Pat. No. 3,179,599 to Eaton et al. (Apr. 20, 1965); The Journal ofthe American Oil Chemists Society, 36 pp. 24l244 (June 1959); TheJournal of the American Oil Chemists Society, 37, pp. 427-430 (September1960); and The Journal of the American Oil Chemists Society, 45, pp.738-741 (November 1968).

These detergents are termed hereinafter for convenience as alkyl ethersulfates. The alkyl ether sulfates of the invention correspond to theformula R (OC HQ OSO M hereinbefore described. For purposes of thepresent invention, the designation of the value of x as an average valueof from about 1 to about 10 refers to the number of moles of ethyleneoxide reacted per mole of high molecular weight alcohol to form theethoxylated alcohol product which is subsequently sulfated andneutralized to provide the alkyl ether sulfate component of theinvention.

The alkyl ether sulfate component of the invention comprises from 1% to20% by weight of the liquid detergent composition of the invention.Preferred from the standpoints of desirable sudsing and economicconsiderations is an amount of from 2% to 18%.

The alkyl ether sulfates of the invention can be prepared by sulfationand neutralization of a condensate prepared by reaction of from 1 to 10moles of ethylene oxide per mole of a monohydric alcohol having fromabout 10 to about 16 carbon atoms. Suitable alcohols for preparation ofthe condensate include those derived from fats and synthetic alcohols.Examples of these alcohols include decyl alcohol, dodecyl alcohol,oxobased tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol andalcohols derived by reducing fatty oils such as coconut oil, palm oil,kernel oil, babassu oil, coconut fatty acids or their alkyl esters.Chain lengths of less than ten carbon atoms give reduced detergency andsudsing while those greater than 16 tend to reduce the quantity of sudswhich are produced. Preferred alcohols are the straight-chain alcoholshaving from 12 to 14 carbon atoms and wherein at least of the alkylgroups contain 12 carbon atoms. Especially preferred herein are thealcohols corresponding in chain lengths to the middle-cut coconutalcohols. The term alkyl is intended to include the olefinic as well astrue alkyl groups and includes those derived from fatty origin such asoleyl alcohol and the like.

Sulfation and neutralization of the condensation products of ethyleneoxide and higher molecular alcohol, described hereinbefore, can beconducted by known methods. The sulfated product is neutralized byreaction with an alkali metal base, (e.g., sodium hydroxide, potassiumhydroxide) ammonium hydroxide or alkylol-substituted ammonias to provideradicals corresponding to M hereinbefore defined. Preferredalkylol-substituted ammonias are mono-, di-, and triethanol amines,mono-, di-, and tri-isopropanol amines and mono-, di-, and triglycerolamines, i.e., those in which the alkylol group has from 2 to 3 carbonatoms. Depending upon the neutralizing agent employed in carrying outneutralization of the sulfated alcohol ethoxylate, M in the hereinbeforedescribed formula will be a water-solubilizing-cation such as sodium,potassium, ammonium, trimethanolamine or the like.

Soaps suitable for use in the present invention are the soaps of fattyacids containing from 12 to 14 carbon atoms. It has been found thatsodium soaps of fatty acids having longer chain lengths, e.g., sodium C/C soaps suppress suds formation to an undesirable extent. The fattyacid soaps of the invention can be synthetically prepared byneutralization of fatty acids prepared by known methods (e.g., by theoxidation of petroleum, or by hydrogenation of carbon monoxide by theFischer-Tropsch process). Alternatively they can be separated, as byfractionation, from mixtures of soaps obtained from fatty acids derivedfrom natural sources such as, for instance, from plant or animal esters(e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil,tallow, whale and fish oils, grease, lard, and mixtures thereof).

Mixtures of soap compounds suitable herein include those having apredominating amount, i.e., at least about 80%, of soap compounds in theC to C range. A preferred mixture of soaps is that derived byfractionation of middle-cut coconut alcohol having the followingapproximate chain length distribution: 3% C 2% C 66% C 20% C and 9% C tosubstantially remove soaps outside the C range. The specificity of thefatty acid soap is very important to suds height stability.Unfractionated coconut fatty acid soap mixtures, for example, areunsatisfactory from the standpoint of suds stability.

The alkyl ether sulfate and soap components together comprise from 3% to20% of the compositions of the invention. The weight ratio of alkylether sulfate to fatty acid soap is about 1:1 to 20:1; the preferredratio is from about 2/1 to 10/ 1. Normally, the total soap content ofthe composition is from about 0.5% to 5.0% by weight, especially from1.0% to 2.0% by weight of the total composition. Normally, the totalamount of water is at least about 60% to 80% by weight of thecomposition. The amount of water and other components will beproportioned to provide solubilizing effects so as to form a homogeneousliquid.

The present invention enables the provision of heavy duty liquiddetergent compositions having excellent sudsing profiles and mildnessproperties. A preferred composition of the invention consistsessentially of: (a) about 2% to 18% by weight of a sodium alkyl ethersulfate containing an average of 3 ethylene oxide groups and wherein thealkyl contains from about 10 to 16 carbon atoms; (b) about 1.0% to 2.0%by weight of an alkali metal soap having from 12 to 14 carbon atoms; (c)from about 5% to 20% of a water-soluble builder salt; and (d) from 60%to 80% water.

Sequestering or buffering builders can be employed in the compositionsof the invention. Suitable builders include the water-soluble organicand inorganic builders.

Water-soluble inorganic alkaline builder salts which can be used in thisinvention alone or in admixture are alkali metal carbonates, borates,phosphates, polyphosphates, bicarbonates and silicates. Ammonium orsubstituted ammonium, e.g., triethanol ammonium, salts of thesematerials can also be used. Specific examples of suitable salts aresodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodiumand potassium pyrophosphate, sodium and ammonium bicarbonate, potassiumtripolyphosphate, sodium hexaphosphate, sodium sesquicarbonate, sodiumorthophosphate, potassium bicarbonate, and the sodium salts ofnitrilotriacetic acid. The preferred inorganic alkaline buildersaccording to this invention are the alkali metal pyrophosphates.Potassium is the preferred alkali metal used in liquid compositions.

Examples of suitable organic alkaline builder salts used in thisinvention alone or in admixture are alkali metal, ammonium orsubstituted ammonium, aminocarboxylates, e.g., sodium and potassiumethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl)-ethylenediaminetriacetates, sodium and potassiumnitrilotriacetates and sodium, potassium and triethanolammoniumN-(2-hydroxyethyl)- nitrilodiacetates. Mixed salts of thesepolycarboxylates are also suitable. The alkali metal salts of citricacid can be suitable employed. The alkali metal salts of phytic acid,e.g., sodium phytate are also suitable as organic alkaline sequestrantbuilder salts (see US. Pat. No. 2,739,942).

Polyphosphonates are also valuable builders in terms of the presentinvention including specifically sodium and potassium salts ofethane-l-hydroxy-l,1- diphosphonic acid, sodium and potassium salts ofmethylene diphosphonic acid sodium and potassium salts of ethylenediphosphonic acid, and sodium and potassium salts ofethane-1,1,Z-triphosphonic acid. Other examples include the alkali metalsalts of ethane- 2-carboxy-1,l-diphosphonic acid,hydroxymethanediphosphonic acid, carbonyldiphosphonic acid, ethane-1-hydroxy-1,l,2-triphosphonic acid, ethane-Z-hydroxy-1,1,2-triphosphonic acid, propane-1,1,3,3-tetraphosphonic acid,propane-l,l,2,3-tetraphosphonic acid, andpropane-1,2,2,3-tetraphosphonic acid.

The compositions of the invention provide a pH in washing solutions inthe range of from 7 to l l. The pH will vary depending upon the presenceor absence of builder salts, the amount of such salts employed and thelike. Built formulations will normally have a pH in the range of from 10to l 1 and provide excellent cleaning results for hard surfaces whichhave high fat, greasy type soils. Unbuilt compositions will provide a pHin solution in the range of 7 to 11.

Minor ingredients can be included in the formulations to give theinvention certain desirable characteristics. For example, preservatives(such as formaldehyde), perfumes, dyes and solubilizing agents can beadded without affecting the desirable properties of the invention.Suitable optional surfactants for use herein include linear alkylsulfates, nonionics, zwitterionics and amides.

A hydrotrope agent can be employed in the compositions of thisinvention; suitable hydrotropes herein are the watersoluble alkali metalsalts of toluene sulfonate, cumene sulfonate, benzene sulfonate, xylenesulfonate and the like. The preferred hydrotropes are the potassium orsodium toluene sulfonates and cumene sulfonates. The hydrotrope salt canbe added, when desired, at levels of 1% to about 12% by weight of thecomposition, preferably from 8% to Normally, a hydrotrope is added toaid in rendering the product homogeneous.

The compositions of this invention are prepared by conventional methods;for example, the constituents of the compositions can be mixed togetherin the presence of, e.g., about 70% water, with agitation or stirring toprovide a substantially homogeneous solution.

Foaming characteristics of hard surface cleaning formulations areimportant from the standpoint of the average housewife. Product cleaningpower is usually associated with the suds height or stability of thesecompositions. The compositions of the present invention exhibitdesirable foaming and cleaning characteristics tervals the mop waspulled out of the solution and squeezed. The process was continued for atotal of 60 seconds and another suds reading was taken (suds readingtime, 2). The sequence was continued for each additional suds heightreading. A total of 60 seconds was consumed for every suds heightreading. City tap water containing from 7 to 10 grains/gallon ofhardness was employed.

An optimum suds level of alkyl ether sulfate/soap blends is from 2 to5.5 inches; values below 1 inch or above 6 inches are consideredundesirable.

The following Examples illustrate preferred embodiments utilizing C or Cfatty acid soaps in combination with an alkali metal alkyl ethersulfate.

Ingredients Example I Example ll Example 111 Example lV Control R--O-(CHCH O) SO M 17.5% 2% 17.5% 2% Na C soap (92% C 5% C 3% C 1.75% 1% Na Csoap (93% C 1.75% 1% 3% 10; 3% C14) Sodium tripolyphosphate 10% 10%Sodium carbonate 4.0% 4.0% Sodium toluenesulfonate 8.0% 8.0% 8.0% 8.0%8.0% Minor ingredients (i.e., dyes,

perfumes, etc.) 0.5% 0.5% 0.5% 0.5 0.5% Water 71.25% 74.50% 71.25% 74.5%69.50% pH 7.8 10.5 7.8 10.5 7.8 Unfractional middle-cut coconut sodiumsoap 2% R Middle cut coconut (3% C 2% C 66% C11; 20% C 9% C x 3 (averagevalue) M Sodium at use concentration and at the same time are mild tothe skin.

The compositions of the invention can be used for either commercial orhousehold hard surface cleaning operations with only minimal waxremoval, thereby leaving a rebuffable surface after washing. Thesecompositions can be used to clean a wide variety of surfaces withoutfear of damage to the surface. The unbuilt formulas (e.g., neutralcompositions) are especially suited to use in hard surface cleaningoperations with minimized detergent or alkali burn or irritation to theuser. No rinsing is required after washing and streaking is minimizedbecause of the low residual suds. The suds height and concentration arestable enough to promote excellent cleaning of the surface beingcleaned.

The following compositions, in which the percentages are by weight, willserve to illustrate but not limit this invention. Each of thecompositions in the Examples gives in solution a pH within the desiredrange of from about 7.5 to about 10.5.

EXAMPLES I IV The household usage suds test (HUST), which was used toevaluate compositions of the invention, was conducted by allowing 1gallon of water (at specified hardness and temperature) to run from thefaucet into a bucket containing one-fourth cup of the cleaning solution.The cleaning solution was located in the bottom of a two-gallon pail.The suds height (in inches) was read immediately. The initial sudsreading corresponds to suds reading time zero. One minute later, thesuds height was again read (suds reading time, 1). A sponge mop wasdipped into the solution and at 10-second in- The compositions ofExamples 1 to [V are illustrative of built and unbuilt formulations ofthe present invention.

The compositions of Examples 1 to IV were evaluated using the method setforth in the household usage suds test. The compositions had a waterhardness of 7 grains/gallon and a temperature of 1 15F. For comparisonpurposes, the control sample described hereinbefore was evaluated forsudsing profiles. The unfractionated control sample was derived from themiddle cut of coconut alcohol having the following chain lengthdistribution: 3% C 2% C 66% C 20% C and 9% C Compositions l to 1V inTable I correspond to the respective examples described hereinbefore.The results were as follows:

TABLE I Suds Reading Height (inches) at Stated Time Intervals The builtand unbuilt compositions of the invention provide suds heights withinthe desired sudsing height ranges. The unfractionated coconut soap gaveunfavorable sudsing profiles in combination with an alkyl ether sulfateof the invention. The suds height was low initially and during thecourse of the evaluation.

The following Examples are illustrative of the present invention, but itwill be understood that the invention is not in any way limited thereto.

EXAMPLE V Sodium salt of coconut alkyl ether sulfate (obtained from thecondensate of 2 moles ethylene oxide per mole of alcohol) 20.0% Sodiumtetradecanoate 2.0 Sodium cumene sulfonate 8.0 Water 70.0

This composition is a sudsing liquid cleaner which provides excellentperformance results on hard surfaces such as walls, floors, ceilings andthe like.

EXAMPLE VI Sodium salt of coconut alkyl ether sulfate (obtained from thecondensate of 3 moles ethylene oxide per mole of alcohol) Sodiumtetradecanoate Tetra-potassium pyrophosphate Sodium carbonate/sodiumbicarbonate Sodium cumene sulfonate Water 7 This composition is aneconomical liquid cleaner offering excellent performance when used at arecommended usage level of one-fourth cup per gallon of water. In such awashing solution the composition has a pH in the range of about 10 to11.

EXAMPLE VII Sodium salt of tallow alkyl ether sulfate (obtained from thecondensate of 4 moles ethylene oxide per mole of alcohol) 2.0% Sodiumtetradecanoate 1.0 Tri-sodium salt of nitriloacetic acid 12.0 Sodiumcarbonate/sodium bicarbonate 2.5 Sodium cumene sulfonate 8.0 Water 74.5

This is a sudsing liquid cleaner composition with superior performanceproperties when used at a recommended usage of one-fourth cup per gallonin an aqueous solution having a pH in the range of 10 to 1!.

EXAMPLE VIII Sodium salt of coconut alkyl ether sulfate (obtained fromthe condensate of 3 moles ethylene oxide per mole of alcohol) 14.0%Sodium dodecanoate 1.5 Potassium toluene sulfonate 6.0 Water 78.5

This composition is a controlled sudsing liquid cleaner which providessuperior cleaning performance at recommended usage levels in the rangeof one-eighth cup per gallon to about three-eighths cup per gallon ofLII water. The washing solution has a pH in the to 11.

range of 7 EXAMPLE IX Sodium salt of tallow alkyl ether sulfate(obtained from the condensate of 4 moles ethylene oxide per mole ofalcohol Sodium dodecanoate Pentasodium tripolyphosphate Sodiumcarbonate/sodium bicarbonate Potassium toluene sulfonate Water Thiscomposition is a medium sudsing liquid cleaner having a pH of about 10and which gives superior performance characteristics when used accordingto rec-' wherein R is alkyl of from 10 to 16 carbons, x has an averagevalue of .from 2 to 4 and M is a watersolubilizing cation selected fromthe group consisting of alkali metal, ammonium, and substitutedammonium; and from 0.5% to 5% of an alkali metal soap selected from thegroup consisting of alkali metal soaps containing 12 carbon atoms,alkali metal soaps containing 14 carbon atoms, mixtures of alkali metalsoaps, said mixtures containing at least 92% of a soap containing 14carbon atoms, and mixtures of alkali metal soaps, said mixturescontaining at least 93% of a soap containing 12 carbon atoms; and thebalance water; said alkyl ether sulfate and alkali metal soap being inthe ratio of from 1:1 to 30:1.

2. The composition of claim 1 wherein the alkyl ether sulfate and alkalimetal soap comprise from 3% to 20% of the composition.

3. The composition of claim 2 wherein the alkali metal is sodium.

4. The composition of claim 3 wherein x has an average value of 3.

5. The composition of claim 4 having a water-soluble builder salt theratio of alkyl ethersulfate and soap to builder being from 1:1 to about1:10.

6. The composition of claim 5 containing additionally from 1% to 12% byweight of the composition of a hydrotrope, said hydrotrope beingselected from the group consisting of sodium toluene sulfonate, sodiumcumene sulfonate or sodium xylene sulfonate.

7. The composition of claim 6 wherein the water is 60% to by weight ofthe composition.

2. The composition of claim 1 wherein the alkyl ether sulfate and alkali metal soap comprise from 3% to 20% of the composition.
 3. The composition of claim 2 wherein the alkali metal is sodium.
 4. The composition of claim 3 wherein x has an average value of
 3. 5. The composition of claim 4 having a water-soluble builder salt the ratio of alkyl ethersulfate and soap to builder being from 1:1 to about 1:10.
 6. The composition of claim 5 containing additionally from 1% to 12% by weight of the composition of a hydrotrope, said hydrotrope being selected from the group consisting of sodium toluene sulfonate, sodium cumene sulfonate or sodium xylene sulfonate.
 7. The composition of claim 6 wherein the water is 60% to 80% by weight of the composition. 